<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <script src="vue.js"></script>
</head>
<body>
    <div id="div1">
        <input type="text" v-model="n1">

        <select  v-model ="opt">
            <option value="+">+</option>
            <option value="-">-</option>
            <option value="*">*</option>
            <option value="/">/</option>
        </select>

        <input type="text" v-model="n2">
        <input type="button" value="=" @click = "jSuan">
        <input type="text" v-model="resuly">
    </div>
    <script>
        var vm = new  Vue({
            el : "#div1",
            data :{
                n1 : 0,
                n2 :0,
                resuly : 0,
                opt : "+",

            },
            methods: {
                jSuan(){
                    if (this.opt == "+"){
                        this.resuly = parseInt(this.n1) + parseInt(this.n2)
                        }
                    else if(this.opt == "-"){
                        this.resuly = parseInt(this.n1) - parseInt(this.n2)
                    }
                }
            },
        })
    </script>
</body>
</html>